Drilling apparatus



May 4, 1943.

F. H. MUELLER ET AL DRILLING APPARATUS Original Filed "Jul 17, 1940 Jnmcmlow Patented May 4, 1943 DRILLING APPARATUS Frank H. Mueller and Walter,J. Bowan, Decatur, Ill., assignors to Mueller 00., Decatur, Ill., a corporation of Illinois Original application July 17, 1940, Serial No. 346,052. Divided and this application December 12, 1941, Serial No. 422,768

7 Claims.

This invention relates to drilling apparatus and particularly to drilling apparatus of the type used in drilling. and tapping an opening in a main without substantial loss of pressure fluid in the main. An object of the invention is to provide means for effectively centering the bit, the latter, as particularly contemplated herein, including drilling and tapping portions. One manner of carrying out the invention will be described with reference to the embodiment shown in the accompanying drawing in which:

Figure l is an axial section of a drilling machine in accordance with the invention, the view also including a partial transverse section of a main with which the machine is operatively associated, and

Figure 2 is a section substantially on line 2-2 of Figure 1.

Referring to the drawing, reference numeral l designates generally a housing or barrel comprising outer and inner portions II and I2 threaded together. The inner portion I2 is packed against a saddle I3 which in turn is packed against the main I4 in which a hole is to be drilled and tapped, the barrel being held in substantially radial position by means of a tensioned belt, not shown, passed around the main and having its nds secured to suitable anchoring means, not shown, on a collar l5 which surrounds portion II and rests against the top rim of portion l2.

A cap I6 is threaded on the outer end of portion H and sealed against the upper end of the latter. The cap has an outer extension or neck l1 provided with external threads engaged by a feed nut I8 equipped with handles l9, and pivoted to the nut is a yoke which engages over an abutment 2| on a boring bar 22 which is rotatable and reciprocable in an axial bore of neck H. The bar 22 can be operatively advanced by threading nut 18 downwardly on neck H and the bar is. enabled to be rotated by means of a suitable tool applied to its squared upper extremity 23.

At its inner end bar 22 is provided with a head 24 in which is formed a socket which receives the shank 25 of a bit or tool 26 having a drilling portion 21 surmounted by a tapping portion 28, the shank of the bit being retained in the socket by any suitable means such as a set screw 29.

Theupper end of barrel portion I2 is inwardly thickened to. providea constriction 30 which pre sents a cylindrical guide surface 3i coaxial with the bore of neck 11, the upper edge of the surface being preferablybeveled, as shown. As here shown thetconstriction is otrestricted length and is disposed about midway between the ends of the barrel It], the chamber portions above and-below the constriction being of substantially greater cross sectional area than the latter. The diameter of the cylindrical guide surface-hoivever"; is sufiicient to freely pass the-toolZB and the head 25 of the boring bar. The constriction te-r minates downwardlyv in a flat shoulder 32 which serves as a seatfor cooperation with the packing 33 carried by a flop valve which is operatively mounted on a rock shaft 35.

Setagainst a shoulderfiiof head 24 isa cylindrical disc 31 which is retained by a threaded ring 38 or other appropriate means, the disc being coaxial with the boring bar. The diameter of"- discv 31 is such that the disc is enabled to be closely received in the constriction 133ml" the purpose of accurately centering the lower end; .of thepboring bar and, therewith the 17001 26, the

disc rotating in and axially traversing the cen-- striction during the drillingoperation. The ,disc

may be formed of metaL; rubber or leather, the. material being such preferably as not to be readily chipped or ,burred.

In theuse of the apparatusthe;barrel is first mounted onthe main in the absence of cap 10,; boring bar 22, and their associated equipment.

The boring bar is now inserted in the upper barrel portionand the cap is threaded on the latter. It,

not infrequently occurs thatthe barrel has to Q0, cupy a radially tilted position relative to the main and the space between itsupperend and mead--- jacent wall of the excavation may be so restricted,

that it would be impossible to insert the; boring bar in the barrel portion l I .by directaxialmove ment. Such direct axial movement would be required if the diameter of the upper barrel portion werethe same as that of, the constriction 3i), but,- in View of the greater internal diameter, of portion II and the consequent tiltability of discsl therein, the boring bar can be inserted at an angle.

to theaxis of the barrel and then alignedso that.

the cap It can be screwed on.

The relation of parts is. such. that when. the:

boring bar is advanced disc -31 will enter con.

striction 3%) just before the point of the drill engages the main. Consequently, when engagement of the drill occurs it will be. accurately cen.- I tered with respect tothe barrel and this centering" efiect will continue asthe main is pierced. Just;

before the tapping portion 28 enters the drilled hole, however, disc 37 passes beyond constriction 39 so that its centering effectceases and-the tapping portion is f-ree-toseek itsown-adjlust- Jment so that undue strains which might otherwise be placed thereon are avoided. It may be men tioned that in the illustrated construction advance of the boring bar in conformity with the pitch of the tapping threads is effected during the tapping operation through engagement of threads 39 and 40 but this is no essential with respect to the invention claimed herein.

In the fully developed form of the invention as illustrated, therefore, manipulability in assembly of the boring bar with the barrel is retained, the tool is rigidly centered during drilling but is free to adjust itself during the tapping operation, and the lower shoulder of the centering constriction is utilized as a seat for the flop valve. Needless to say, we do not confine ourselves to the precise details of the illustrated form and arrangement of parts, the invention embracing also variations coming thereunder as defined in the claims.

This application is a division of our application Serial No. 346,052, filed July 1'7, 1940, now Patent No. 2,291,979, issued August 4, 1942.

We claim:

1. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry a drill at its inner end, said barrel having spaced below its outer end an internal constriction providing a cylindrical guide surface of sufficient diameter to pass the drill and the inner end of the bar, and centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the

arrangement being such that said centering.

means enters said constriction just before a drill carried by said bar engages the main as the bar is moved inwardly.

2. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry a drill at its inner end, said barrel having an annular constriction intermediate its ends providing an internal cylindrical guide surface of restricted longitudinal extent and of sufficient diameter to pass the drill and the inner end of the bar, and centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the arrangement being such that said centering means enters said constriction just before a drill carried by said bar engages the main as the bar is moved inwardly.

3. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry a drill at its inner end, said barrel having an annular constriction intermediate its ends providing an internal cylindrical guide surface of restricted longitudinal extent and of sufficient diameter to pass the drill and the inner end of the bar, centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the arrangement being such that said centering means enters said constriction just before a drill carried by said bar engages the main as the bar is moved inwardly, said constriction terminating inwardly in an annular shoulder, and

a flop valve cooperating with said shoulder as a,

seat.

4. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled and tapped, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry at its inner end a tool having drilling and tapping portions, said barrel having an annular constriction intermediate its ends providing an internal cylindrical guide surface of restricted longitudinal extent and of sufficient diameter to pass the tool and the inner end of the bar, and centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the arrangement being such that upon moving said bar inwardly said centering means enters said constriction just before the drilling portion of a tool carried by said bar engages the main and leaves said constriction before the tapping portion of the tool engages the hole formed by the drilling portion.

5. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled and tapped, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry at its inner end a tool having drilling and tapping portions, said barrel having an annular constriction intermediate its ends providing an internal cylindrical guide surface of restricted longitudinal.

extent and of sufiicient diameter to pass the tool and the inner end of the bar, centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the arrangeconstriction before the tapping portion of the tool engages the hole formed by the drilling portion, said constriction terminating inwardly in an annular shoulder, and a flop valve cooperating with said shoulder as a seat.

6. In a drilling machine, a barrel adapted to be disposed in substantially radial relation to a main to be drilled and tapped, closure means for the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry at its inner end a tool having drilling and tapping portions, said barrel having an internal .cylindrical guide surface terminating inwardly in an annular shoulder beyond which the barrel has a I centering means passes beyond said shoulder' after the drilling portion of a tool carried by said bar has engaged the main and before the tapping portion of the tool has engaged the main.

7. In a drilling machine, a barrel adapted to t be disposed in substantially radial relation to a main to be drilled and tapped, closure means forv the outer end of said barrel, a boring bar rotatable and reciprocable in a bore provided in said closure means and arranged to carry at its inner end a tool having drilling and tapping portions, said barrel having an internal cylindrical guide surface terminating inwardly in an annular shoulder beyond which the barrel has a cross.

sectional area greater than that of said guide surface, the diameter of said guide surface being sufiicient to pass the tool and the inner end of the bar, centering means on said bar adjacent the lower end of the latter cooperative with said guide surface, the arrangement being such that upon moving said bar inwardly the centering means passes beyond said shoulder after the drilling portion of a tool carried by said bar has engaged the main and before the tapping portion of the tool has engaged the main, and a flop 5 valve cooperating with said shoulder as a seat.

FRANK H. MUELLER. WALTER J. BOWAN. 

